The present invention relates to the field of Young's modulus measurement; more specifically, it relates to a method and system for determining the Young's modulus of porous thin films using ultra-low load nano-indentation.
In the semiconductor industry porous insulators are used as insulating layers in the wiring level of integrated circuits. In determining the suitability of porous insulators for use in integrated circuits, an accurate measurement of the Young's modulus of the insulator is a necessity. However, when such insulators are formed on silicon substrates it is fully accepted in the art that because of a “substrate effect”, nano-indentation measurements of Young's modulus must be limited to an indentation depth of about 10% of the low-k sample thickness and that nano-indentation will overestimate Young's modulus for such materials by 100%. This renders the values so obtained virtually useless for suitability modeling purposes and requires extensive resources be spent on physical test structures. Accordingly, there exists a need in the art to eliminate the deficiencies and limitations described hereinabove.